1. Field of the Invention
The present invention relates to a cryptosystem, and more particularly, to a cryptosystem for encrypting digital image or voice files.
2. Description of the Prior Art
Internet has become the most important data communication channel in modern society. Many data files such as text files, image files and voice files are usually transmitted between users as electronic mails through Internet. Since each electronic mail has to pass through several Internet servers before it can be received by a target user, security of the electronic mail in the transmission process becomes an important issue. Since there is no way to guarantee that an E-mail can be safely transmitted without being copied by other people, data encryption is usually used before transmitting a data file.
A traditional cryptosystem usually encrypts the original image or voice file by rearranging the data contained in the original file. Such encrypted file usually attracts an illegal intruder's attention and make it a target of the intruder.